Hello Group
Ive had a Daystar .8 H alpha filter kept in its box since the 80s (except when used!)
About five years ago I brought it out and it was acting normal.Back in the Box again.

Getting back into again
Been working on repairing the clock drive on the SCT it rides on.
For the heck of it I set the Scope up and notice the filter itself did not warm as usual when plugged in

Also saw no prominences or magnetic lines.
I am not seeing H alpha . Looks much like a white light image.only Red.

Maybe lil grassfire effect on limb, thats about it.

Oh , and the Bourns knob pot got HOT on high.
No position seemed to change view.
And filter unit (huge) would warm under normal use.(its electric!) But Cold now

This was copy n paste from cloudy nights(hope okay to do)

>>>Dave,
Two things might have happened. The blocking filters have drift off band which is very common for a filter that is as old as yours. The other issue is that the Etalon could have become separated. It's made of mica and placed between two plates with optical grease hold it together I would contact Mark Wagner at Solar Spectrum. He worked for Del Woods and built the units. He repaired a filter for me a few years ago.>>>

This sounds like 0.5A University model a friend asked to check out last summer. The filter coating all look fine, but there was only a hint of Ha when the camera was connected and no amount of tuning (temp control dial) made any difference, so we suspect the heater or controller has had the biscuit.

Thats odd, I replied to this post but I don't see it.
Well the control circuit used in the old Daystar controllers goes back to Carson(that is who Del worked for before he started DayStar). The control chip are really hard to fine now days. The circuit has its disadvantages,they only work correctly in a sine wave . Also if you use a low cost PWM inverter it will burn it up. I am sure that is why the new DayStar changed it to there new controller. For me, I usually just change them out to a digital temperature controller. It cost less then $200 and they work with any inverter and controls better. All your doing is just controlling a strip heater.
Mark W.